Many patients who receive gastric banding surgery for weight loss experience major complications 12 years later, and as many as half of patients eventually have their bands removed, a new study reports.

Laparoscopic adjustable gastric banding surgery (LAGB), which is also commonly referred to as Lap-Band surgery, has become a popular alternative to gastric bypass surgery — the two are the most frequently used bariatric procedures. Lap-Band surgery, which the Food and Drug Administration approved for use in an additional 11 million obese patients in February, involves placing an inflatable band around the upper stomach, which limits the amount of food the stomach can hold. In gastric bypass, the surgeon staples off a section of the stomach, and food is rerouted to bypass the small intestine. (More on Time.com:Weight Loss Surgery May Change the Shape of Your Heart)

The new study looked at 82 patients who had undergone gastric banding between 1994 and 1997. The researchers followed up with the patients in 2009 to see how they had fared over the long term. Nearly 40% of patients had experienced serious complications, and another 22% had had minor ones. Sixty percent needed to undergo subsequent surgery, and 1 in 6 opted to have gastric bypass. “The high failure rate of LAGB, at least in our hands, could be detrimental to its future continued widespread use as a restrictive weight loss operation,” wrote the authors.

Despite the high rate of complications, 60% of patients surveyed said they were satisfied with their surgery. On average, patients in the study maintained weight loss of about 43% of their excess weight, and reported good quality of life. (More on Time.com:Why White Girls Are Getting More Weight Loss Surgery)

Still, in editorial accompanying the study, published Monday in the Archives of Surgery, Dr. Clifford W. Deveney, a professor of surgery at Oregon Health and Science University in Portland, concluded that the new “data do not shed a favorable light on the use of LAGB.” HealthDay reported:

“The band has a spotty history,” Deveney said. “Some groups have very good results, with 60 to 70 percent weight loss. But other groups have either poor weight loss or complications, or both.”

“So I think,” he continued, “that the patient should be made aware of these facts, and also that the weight loss is going to be less with the band than with a gastric bypass. And that it’ll take longer to achieve the weight loss, because with gastric bypass most of the weight loss occurs over the first year, while with a band it takes five to six years.”

“It’s also easier to ‘cheat’ on the band,” he added. “You can eat around the band and render it ineffective if you’re not disciplined in following a healthy diet. With gastric bypass that’s not as much of an issue. But all this is not to say that I think we shouldn’t be doing bands. It’s just not as good as bypass.”

As for the new study, however, some experts say it should not necessarily turn patients away from gastric banding. For one thing, the study looked at patients who had the procedure a long time ago; the surgical technique and the band itself have changed in the interim. “In some ways it is a bit of a historic snapshot of this type of surgery 15 years ago. I would take these results with a grain of salt.” Dr. Marc P. Michalsky, surgical director for the Center for Healthy Weight and Nutrition at Nationwide Children’s Hospital in Columbus, Ohio, told Reuters Health.

[Allergan, which makes the Lap-Band], also noted that the study was based on only 151 patients from a single hospital, and that the researchers had only been able to test half of those patients.

“We are disappointed to see the publication of an ill-constructed, single-center clinical assessment that does not meet the high clinical standards one should expect from peer-reviewed data, and is not reflective of today’s clinical standards,” Cathy Taylor, Allergan’s director of Corporate Communications, said.

The lead author of the new study, Dr. Jacques Himpens of the European School of Laparoscopic Surgery at the Saint Pierre University Hospital in Brussels, acknowledged that “the high failure rate of the band gastroplasty [in] the long term is not that much worse than other procedures,” according to HealthDay. “It is still defendable for surgeons to continue doing it” he said, but patients who choose it should be prepared for diligent long-term follow-up care.